[Bf-committers] Node Unification.. it's a bit winded

[Mathias Panzenböck]

I'm an outsider (not a blender developer) but observed a lot of this discussion. 
Maybe a compromise would be feasible:
While there are certain things that can't be unified because of how the 
different node systems work (e.g. operates on image buffers where you can access 
all pixels Vs. the call of a function per pixel that calls another function on 
maybe another pixel) some nodes similar in all systems could be unified.

Some functions need no more than to get a value (no need for context 
information, no need to get the value of another coordinate), make some 
calculations with it and deliver the result value. I think it might be possible 
to implement a node type for this case and implement appropriate adaptors (maybe 
just C macros to speed it up) in all node systems so nodes of this type can be 
plugged into all node systems. Nodes that can be reduced to this logic (and are 
already there in more than one node system, and have duplicated code, and 
actually had bugs because of the code duplication for which I provided a patch 
that got committed to svn ages ago which makes me proud) would be:
  * All kinds of color operations like separate/combine RGBA/HSVA/YUVA, color
    curves etc.
  * Math
  * ...

Things that would not be possible with this generalized nodes and for what 
therefore specialized nodes in each node system have to be written would be:
  * Blur
  * Rotate/Translate/Scale
  * ...

So rather than completely unifying the node systems to a single one just 
providing support for such *simple* nodes in each system in order to reduce code 
duplication would seem reasonable to me. Basically you would have the node 
types: SHD, TEX, MAT and SPL (for simple nodes). Nodes written for the latter 
type would immediately be available in each system.

	-panzi

PS: Now its 3am here too (Austria), so I hope I haven't written a lot of 
nonsense. I'll go to bed now, good night.

joe wrote:
> Honestly, I don't think we're ever going to have a unified node tree system,
> at least from  the UI perspective of things.  It's just too potentially
> unstable.
> 
> Joe